For the black strip you can change the +80 for whatever extra size the screen has (just try a few values). But if it still crashes then you are out of luck, sorry !. Koreader doesn't know if Google Play is installed so that won't help.
I think the developers are working on better android support for the next release so it might be a good idea to report a bug to
https://github.com/koreader/koreader/issues, at least let them know that it won't work on that device (and maybe adding a logcat too).
Good luck with that !